Tylen

Exception Handling and Weight Conversion

Mar 7 2008 5:29 PM

Hey all,

So, for my final in C# we have to write a few programs. Some of them being pretty simple. The one I'm doing now asks me to write a weight conversion program with a minimum of grams, ounces, kilograms and pounds. If the user enters a negative number or a letter then it's supposed to throw and handle an exception. Well, everything was going great until I encountered this problem.

At the moment, I'm trying to convert grams to kilograms, pounds and ounces. It works great when I'm converting grams to ounces or kilograms, but whenever I want to convert the grams to pounds, it handles an exception and says "Invalid input value.". I have the user select what they want to convert said grams to by inputting a number. The number for pounds is 3, but whenever the user enters 3 to convert to pounds it handles said exception.

Here's my code:

WeightConverterTest Class

using System;
using System.Collections.Generic;
using System.Text;

namespace Final_Question_3
{
    class WeightConverterTest
    {
        static void Main(string[] args)
        {
            //declare variables
            int selection = 0;

            while (selection < 5)
            {

                try
                {
                    //prompt user to select a measurement type to be converted
                    Console.WriteLine("Select measurement type:" +
                        "\n1) Grams\t2) Kilograms\t3) Ounces\t4) Pounds\n" +
                        "5) Exit the program.\n");
                    selection = Convert.ToInt32(Console.ReadLine());

                    /*if statement which checks if the user wanted to end the
                      program of if they entered a selection between 1 and 5*/
                    if (selection == 5)
                        Console.WriteLine("Exiting program.");
                    else if (selection < 1 || selection > 5)
                        Console.WriteLine("Please enter a selection between 1 and 5.\n");
                    else
                        SelectionMethod(selection);
                }//end try
                //if input value is not numeric, display message
                catch
                {
                    Console.WriteLine("Invalid input value.");
                }//end catch
            }//end while

        }//end Main method

        public static int SelectionMethod(int s)
        {
            //declare variables and create reference to WeightConverter class
            WeightConverter weightConverter = new WeightConverter();
            decimal grams = 0;
            decimal kilograms = 0;
            decimal ounces = 0;
            decimal pounds = 0;


            try
            {

                switch (s)
                {
                    //if user chose to input grams, prompt user to enter how many
                    case 1:
                        Console.WriteLine("Input amount of grams to be converted:\n");
                        grams = Convert.ToDecimal(Console.ReadLine());

                        //call Grams method of class WeightConverter
                        weightConverter.Grams(grams);

                        break;

                    //if user chose to input kilograms, prompt user to enter how many
                    case 2:
                        Console.WriteLine("Input amount of kilograms to be conveted:\n");
                        kilograms = Convert.ToDecimal(Console.ReadLine());

                        //call Kilograms method of class WeightConverter
                        weightConverter.Kilograms(kilograms);
                        break;

                    //if user chose to input ounces, prompt user to enter how many
                    case 3:
                        Console.WriteLine("Input amount of ounces to be converted:\n");
                        ounces = Convert.ToDecimal(Console.ReadLine());

                        //call Ounces method of class WeightConverter
                        weightConverter.Ounces(ounces);
                        break;

                    //if user chose to input pounds, prompt user to enter how many
                    case 4:
                        Console.WriteLine("Input amount of pounds to be converted:\n");
                        pounds = Convert.ToDecimal(Console.ReadLine());

                        //call Pounds method of class WeightConverter
                        weightConverter.Pounds(pounds);
                        break;
                }
            }//end try
            //if input value is not numeric, display message
            catch
            {
                Console.WriteLine("Invalid input value.");
            }//end catch

            return s;
        }//end Selection method
    }
}

WeightConverter Class

using System;
using System.Collections.Generic;
using System.Text;

namespace Final_Question_3
{
    class WeightConverter
    {
        public decimal Grams(decimal g)
        {
            //declare variables
            decimal kilograms = 0;
            decimal ounces = 0;
            decimal pounds = 0;
            int selection = 0;

            while (selection <= 4)
            {
                try
                {
                    //prompt user to select what they would like to convert grams to
                    Console.WriteLine("Convert grams to?\n1) Kilograms\t2) Ounces \t3) Pounds" +
                            "\n4) Return to first selection.");
                    selection = Convert.ToInt32(Console.ReadLine());

                    switch (selection)
                    {
                        //convert grams to kilograms
                        case 1:
                            kilograms = g / 1000;

                            Console.WriteLine("{0} gram(s) is {1} kilogram(s).", g, kilograms);
                            break;

                        //convert grams to ounces
                        case 2:
                            ounces = g / (int)28.31257;

                            Console.WriteLine("{0} gram(s) is {1} ounce(s).", g, ounces);
                            break;

                        //convert grams to pounds
                        case 3:
                            pounds = g / 453;

                            Console.WriteLine("{0} gram(s} is {1} pound(s).", g, pounds);
                            break;

                        //return to first selection
                        case 4:
                            selection = 5;
                            break;

                    }
                }//end try
                //if value entered is not numeric, display message
                catch
                {
                    Console.WriteLine("Invalid input value.");
                }//end catch
            }//end while
            return g;
        }

        public decimal Kilograms(decimal kg)
        {
            decimal grams = 0;
            decimal ounces = 0;
            decimal pounds = 0;

            return kg;
        }

        public decimal Ounces(decimal o)
        {
            decimal grams = 0;
            decimal kilograms = 0;
            decimal pounds = 0;

            return o;
        }

        public decimal Pounds(decimal p)
        {
            decimal grams = 0;
            decimal kilograms = 0;
            decimal ounces = 0;

            return p;
        }
    }
}

Answers (1)

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